Excavator bucket



July 18, 1944. s U 2,353,685

EXGAVATOR BUCKET Filed Jan. 7, 1943 2 Sheets-Sheet l 2/ I I INVENTOR.

/ ALBEET E. flsxuz flail, 72 Wra p TraeN-Ers July 18, 1944. A. R. ASKUE 8 EXCAVATOR BUCKET Filed Jan. 7, 1943 2 Sheets-Sheet 2 INVENTOR.

0/127 /IL 55/27- 2 145x115 Patented July 18, 1944 EXCAVATOR BUCKET Albert R. Askue, Mentor, Ohio, assignor to The Cleveland Trencher Company, Cleveland, Ohio, a corporation of Ohio Application January 7, 1943, Serial No. 471,553

4 Claims.

This invention relates to an excavator bucket of the type commonly used in connection with trench digging machines, and particularly with machines using a series of buckets interconnected by a continuous chain. More particularly the invention relates to excavator buckets having replaceable cutting or rooter members along their digging edges.

The cutting or rooter members of excavator machine buckets are subjected to very hard usage, particularly when operated in stony soil or in tree lawns where roots are encountered. In the past cutter or rooter members have been provided which were removably mounted on the buckets. However after a short period of use, the constant pounding due to impact between the rooters and stones or roots resulted, either in the destruction of the bucket or permanent attachment of the rooters to the buckets.

The object of the present invention is to provide an excavator bucket with rooters which will be removable throughout the life of the rooter, and which will be so attached to the bucket that they will not destroy the bucket even though subjected to very severe usages over prolonged periods of time.

A further object of the invention is to provide an excavator bucket with side rooters which may be used as desired to increase the width of trench that may be dug with a given size bucket.

Other objects and advantages of the invention will become more apparent from the following description, reference being had to the accompanying drawings in which a preferred embodiment of the invention is illustrated. The essential and novel features of the invention will be summarized in the claims.

In the drawings, Fig. 1 is a top elevation of an excavating bucket embodying the present invention; Fig. 2 is a side elevation of the bucket; Fig. 3 is a front elevation of the bucket, certain portions being broken away to more clearly illustrate the construction thereof; Fig. 4 is a view of a bucket extension used to increase the cutting capacity of the bucket; Figs. 5 and 6 are sectional details, the planes of the sections being indicated by the correspondingly numbered lines on Fig. 3; and Figs. 7 and 8 are sectional details, the planes of the sections being indicated by the correspondingly numbered lines on Figs. 6 and 7 respectively.

Referring now to the drawings in detail, particularly to Figs. 1, 2, and 3, it will be seen that my improved excavator bucket, comprises a scoop-shaped member ID. This member is illustrated as a casting having an enlarged U- shaped forward or digging edge H, and internal boss like formations I2 at its sides having suit able openings M to receive bolts for attaching the bucket to depending lugs carried by links of respective continuous excavator chains, portions of which are indicated by the broken lines l5 in the drawings. The bottom of the bucket is curved upward to form side walls l6 and a rear wall [1. The excavator chain extends across the top of the side walls as indicated in Figs. 1 and 2, so that the tautness thereof will prevent tipping of the bucket while the digging edges engage the earth. The rear wall of the bucket extends upward to a point above the chain. Hence the conveying capacity of the bucket is increased by the area between the two supporting chains.

When digging in hard soil, or where tree roots and the like are encountered, excavator buckets are generally provided with cutters or rooters. Such cutters become dulled and require sharpening at more or less frequent intervals of time. Further the buckets themselves are capable of use long after the cutters are worn out. Therefore it is desirable that cutters be provided which may be removed from the bucket and replaced by'resharpened or new cutters.

Heretofore it has been customary to bolt cuttersin place on the buckets. The severe use to which excavator equipment is ut often results in the shearing of the bolts which retain the cutters in place. On the other hand if the bolts do not shear, the severe impacts on the teeth, during the digging operation, damages either the bolts or bucket adjacent the bolts to such an extent that the cutter cannot be removed without damaging the bucket to such an extent that it is no longer usable. Likewise it has been found that it is dificult to remove damaged buckets from their supporting chain. Excavating in hard soil has been expensive; not only because of the cost of bucket replacements but also because of the loss of time involved in making such replacements.

To overcome these disadvantages I so arrange my improved bucket and cutting teeth as to eliminate the use of bolts, pins or similar members for fastening the teeth to the bucket. I accomplish this by. relying entirely upon frictional contact between the bucket and teeth.

The forward or cutting edge ll of the bucket is provided with a series of spaced sockets 20, the axes of which are the axes of their respective cutting teeth 2|. As may be seen from Fig. 7, the

shanks of the cutting teeth are tapered as at 22 and the sockets are correspondingly tapered as at 23. The tapers 22 and 23 are made at such an angle as to cause the cutter teeth to be firmly engaged by and held in place by a wedging action. The angle of taper in this respect simulates that commonly used to retain engine lathe centers in position and is capable of withstanding severe impacts without danger of the tooth becoming loose and consequently damaging the bucket itself.

the tooth relative to the bucket.

Even though great care is used in selecting the materials for making the bucket and cutting tooth, as well as in designing the taper, it was found that this alone did not provide such removability of the teeth as was desired. The se- Vere impacts on the cutting teeth so drove them I into their sockets that it was extremely diflicult,

,and at times almost impossible to remove them.

An important feature of the present invention is the arrangement of the socket, and that portion of the cutter tooth entering the socket, so that the cutter tooth may be removed re1atively easily despite the hard usage it is. sub- 7 jected to and without decreasing the rigidity of I accomplish this by providing the tooth shank and socket with alternately engaging and non-engagingsurface areas. As shown in Figs. 7 and 8 the tapered surfaces 22 of the tooth are curvilinear in cross section as are the tapered surfaces 23 of the socket. The curvilinear surfaces 2 2 of the tooth are separated from each other by chordal surfaces 2 while the tapered surfaces 23 of the socket are spaced by chordal surfaces 25. The thickness of the tooth is such that the chordal surmined to a large extent upon the cross section a1 area when it is subjected to severe impacts during the excavating operation. By providing noncontacting areas between the socket wall and the teeth this swelling is permitted in such a manner that there will be no binding or riveting of the tooth to the socket. A similar swelling action occurs when the base 26 of the tooth is struck to force it out of the socket. The amount of clearance therefore is preferably such that the tooth may be used for a prolonged period of time and removed for sharpening when required, without danger of completely filling the socket.

The clearance between the socket and tooth is held to a minimum to avoid abnormally increasing the thickness of the cutting edge of the bucket. For this purpose I space the contacting surfaces 22 farther apart than the noncontacting surfaces 24. This not only decreases the tendency of the tooth to spread toward'the contacting surfaces but increases the area in which the tooth may expand without requiring an abnormally great amount of clearance.

As heretofore mentioned it is sometimes desirable to increase the width of the trench. Normally the trench dug is substantially the same width as the bucket, and if a wider trench is desired the buckets are replaced by wider buckets. lhis of course'is an expensive operation, particularly where the extra width is required for only a portion of the trench length. To avoid the disadvantages of the past I provide extensions '30 which maybe removably attached to the bucket.

The bucket extensions 39 are illustrated in place on the bucket in Figs. 1, 2 and 3, and the extension itself is shown apart from the bucket in Fig. 4. As there shown, the extension is in the nature of a bracket comprising an angular cutting tooth carrying arm 3| provided with sockets 2B 1 for receiving cutting teeth. These .As illustrated, one end of the tooth carrying arm is provided with a bucket engaging formation 32 arranged to fit against the enlarged cutting edge ll of the bucket. The formation 32 has a pair of bosses 33 which fit into two of the sockets of the bucket. Suitable bolts 34 passing through the bosses 33 and sockets, secure the extension to the bucket. The strain on these bolts is relieved by a strut formation 36 which extends from a point on the arm 31 remote from the formation 32 to theside wall of the bucket, to which it is bolted by bolts 3?. The abutting surfaces between the buckets and the extension 30 are of such area as to permit the use of bolts as a securing means for the extension.

I claim:

1. A digging bucket for an excavator machine, said bucket comprising a scoop shaped member having a forward cutting edge, a series of sockets formed in said bucket adjacent the cutting edge thereof, rooter teeth removably mounted in said sockets, the walls of the sockets and the associated walls of the teeth having alternately arranged engaging and clearing surfaces, the distance between the engaging surfaces being greater than the distance between the clearing surfaces.

2. A digging member for an excavating machine, said member having a tooth receiving socket, a tooth mounted in said socket, the walls of the opening and the coasting walls of the tooth having alternately arranged engaging and clearing surfaces, the distance between the engaging surfaces being greater than the distance between the clearing surfaces.

3. A digging bucket for an excavator machine, said bucket having a series of spaced sockets arranged in a line along its cutting edge, cutting teeth provided with shanks arranged and adapted to enter said sockets, said shanks having spaced tapered surfaces which engage corresponding tapered surfaces of the socket, there being a substantial clearance between the cutting teeth shanks and their respectivesockets in the regions intermediate the spaced tapered surfaces, and wherein the engaging surfaces of said teeth and socket are those surfaces nearest to the adjacent sockets.

4. A digging bucket for excavator machines, said bucket having a series of aligned'and spaced sockets adjacent its forward digging edge, the side Walls of each of said sockets being formed by spaced arcuate and chorda'l surfaces alternately arranged, the arcuate surfaces of each socket being spaced a greater distance apart than the chord'alsurfaces and wherein the arcuate surfaces of each socket are adjacent the arcuate surfaces of the next adjacent sockets and the chordal surfaces are substantialily parallel with the line of sockets, rooter teeth having portions entering said sockets, said portions having surfaces engaging the arcuate surfaces of said sockets, wherein the surfaces of said teeth are spaced from'the chordal portions of said socket, whereby the teeth when deformed due to successive impacts will not completely fill said sockets.

' ALBERT R. ASKUE; 

